Just offshore of Highway 1 near Marconi Cove lies a submerged graveyard unknown to most: hundreds of old truck tires resting on the floor of Tomales Bay.
Installed in the 1960s as part of a makeshift breakwater meant to protect what was once a small marina, the tires have languished underwater for decades. Historical records from the Army Corps of Engineers describe two tire structures, each roughly 80 to 100 feet long and 15…